[Camron Rust]

Originally Posted by Snaqwells

Okay, so how do you determine which rule comes into play? In the OP, the defender is really guarding by screening.

They indeed are very close and largely overlap except that....

"Guarding is the act of legally placing the body in the path of an offensive opponent...."

The defnintion of screen has no distiction between offense/defense (although you rarely see a defender set a screen).

Being in LGP has certain requirements. If those are not met (e.g., never facing the opponent), it is certainly possible that a legal screen could still be set but the screening principles with regards to subsequent movement are more restrictive than the guarding principles....no lateral movement, for example. Also, a screen requires time/distance even if the opponent has the ball. So, a player could, short of having LGP, set a screen on the offensive player (with or without the ball) without ever facing the offensive player if they give time/distance for the offensive player to stop or change directions.

This is how you have a foul on A1 when A1 runs up the back of stationary B4 who is guarding A4. B4, even unknowingly, set a screen on A1.